OAR Box 1107 

Prepped by Ollie Stewart 

Document Number: 

42) IV-A-1 

Docket Number: 

A-81-21 

Printed 4/11/2008 3:03:46 PM Sheet 42 of 90 

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> ' -

A-81-21 

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IV-A-1 

Benzene Emissions from 

Benzene Storage Tanks — 

Background Information 

for Proposed Standards 

Emission Standards and Engineering Division 

RADIAN LIBRARY 

DURHAM, N. C. 

U.S. ENVIRONMENTAL PROTECTION AGENCY 

Office of Air, Noise, and Radiation 

Office of Air Quality Planning and Standards 

Research Triangle Park, North Carolina 27711 

December 1980 
•i 

Table 3-5. MODEL BENZENE STORAGE PLANTS 

(A) 

ro 

i — • 

Type of Tank dimensions. Existing tank type 

model (diameter/height) (CTG as baseline) 

plant 

(meters) (feet) 

BENZENE PRODUCER 

Large facility (throughput of 224.6 x IO6 liters/year): 

12/9 

18/12 

8/5 

9/9 

13/13 

24/9 

27/15 

(40/30) ncIFR 

(60/39.8) EFRps 

(25/18) cIFRps 

(30/30) cIFRps 

(42/41.8) ncIFR 

(80/30) ncIFR 

(90/48) ncIFR 

Small facility (throughput of 46.3 x IO6 liters/year): 

3/11 

13/13 

8/11 

32/7 

(10/36) FR 

(42/41.8) ncIFR 

(25/35.9) ncIFR 

(104/24) cIFRps 

BENZENE CONSUMER (throughput of 42.1 x IO6 liters/year): 

12/U 

18/15 

BULK STORAGE TERMINAL 

12/11 

18/15 

(42/35.9) ncIFR 

(60/43) cIFRps 

(throughput of 42.1 x IO6 liters/year): 

(40/35.9) ncJFR 

(60/43) cIFRps 

New tank type*' 

(NSPS as baseline) 

ncIFR 

EFRss 

ncIFR 

ncIFR 

ncIFR 

ncIFR 

ncIFR 

FR 

ncIFR 

ncIFR 

ncIFR 

ncIFR 

ncIFR 

ncIFR 

ncIFR 

Tank size 

(IO3 liters) 

980 

2,930 

240 

660 

1,640 

3.990 

8,630 

80 

1,650 

490 

5,280 

1.240 

3.410 

1,240 

3.410 

Annual throughput 

(IO6 liters/year) 

117.1 

38.3 

28.7 

78.8 

21.4 

52.1 

112.8 

6.5 

11.0 

39.8 

35.3 

11.2 

30.9 

11.2 

30.9 

Annual turnovers 

119 (rundown tank) 

13 

119 (rundown tank) 

119 (rundown tank) 

13 

13 

13 

81 (rundown tank) 

7 

81 (rundown tank) 

7 

9 

9 

9 

9 

*FR-fixed-roof tank, EFRps-extemal floating-roof tank with a primary seal, EFRss-external floating-roof tank with primary and 

secondary seals, ncIFR-noncontact Internal, floating-roof tank, cIFRps-contact Internal floating-roof tank with primary seal. 

£ 
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provide estimates of the costs to install fixed or internal floating 

roofs on existing storage tanks (Tables 7-16, 7-17, 7-18, and 7-19). The 

external floating-roof tank CTG was the source of the costs for cleaning, 

degassing, and certifying modified tanks and installing secondary seals 

on external floating roofs (Table 7-20). The secondary seal costs were 

also used to evaluate the costs of retrofitting internal floating roofs 

with secondary seals. 

Because the costs for modifying existing storage tanks were obtained 

for a range of five tank sizes, the cost of modifying each tank in a 

model facility was estimated by performing a straight line linear regression 

analysis on the five paired functions of cost and tank size. These five 

paired functions included: (1) the cost of fitting a roof on an external 

floating-roof tank versus the square of the tank diameter, (2) the cost 

of installing a secondary seal on an internal or external floating roof 

versus the tank diameter, (3) the cost of cleaning, degassing, and certifying a tank versus tank volume, (4) the cost of removing a noncontact 

internal floating roof versus the square of the tank diameter, and (5) the 

cost of installing a contact or noncontact internal floating roof versus 

the square of the tank diameter. 

The capital costs of installing a carbon adsorption or thermal 

oxidation vapor control system to reduce benzene emissions from an existing 

model facility are presented in Tables 7-21 and 7-22, respectively. 

These costs were estimated from information supplied by vendors of the 

control equipment. It was assumed that each system, which was sized to 

recover the emissions from a tank being filled by a barge at a rate of 

7,750 liters/minute (2,000 gallons/minute), was connected to all benzene 

29 

storage tanks at a facility. Approximately 180 meters (600 feet) of 

vapor collection pipe was used to connect each tank to the carbon adsorption or thermal oxidation unit. The carbon adsorption and thermal oxidation 

systems also utilized pressure switches and blowers (see Section 4.2.8). 

Water seals were used to reduce the danger of flashback, and it was assumed 

that an adequate supply of steam was available for regenerating the 

carbon bed if a carbon adsorption unit were used. 

Also included in the capital costs for a carbon adsorption and a 

thermal oxidation system was the cost for safety devices, including a 

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Table 7-16. COST OF INSTALLING A NONCONTACT INTERNAL 

FLOATING ROOF IN AN EXISTING FIXED-ROOF TANK9 

Tank Installed capital cost Cost of cleaning, Total 

dimensions of an aluminum noncontact,. degassing, and, cost 

(meters) internal floating roof ' certification 

8 x 12 

13 x 15 

14 x 17 

21 x 12 

27 x 15 

$ 6,600 

10,550 

11,750 

18,350 

25,450 

1,300 

2,000 

2,500 

3,400 

6,150 

$7,900 

12,500 

14,250 

21,750 

31,600 

aCosts are in first-quarter 1979 dollars, 

Diameter by height 

cGulf Coast installation. 

7-36 
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Table 7-17. COST OF INSTALLING A CONTACT INTERNAL 

FLOATING ROOF IN AN EXISTING FIXED-ROOF TANKa 

Tank' . 

dimensions 

(meters) 

Installed capital 

cost of an aluminum 

contact internal9c 

floating roof c' " 

Cost of cleaning, 

degassing, and, 

certification 

Costs are in first-quarter 1979 dollars. 

'Diameter by height. 

'Gulf Coast installation. 

Total 

cost 

8 x 12 

13 x 15 

14 x 17 

21 x 12 

27 x 15 

$ 9,300 

15,300 

17,500 

32,400 

48,950 

$1,300 

2,000 

2,500 

3,400 

6,150 

$10,600 

17,300 

20,050 

35,800 

55,100 

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Table 7-18. COST OF INSTALLING A FIXED ROOF ON 

AN EXISTING EXTERNAL FLOATING-ROOF TANK* 

Tank diameter 

(meters) 

8 

13 

14 

21 

27 

x 12 

x 15 

x 17 

x 12 

x 15 

cos 

Installed capital. 91 Cost of cleamn 

t of aluminum dome * * degassing, and 

$ 7,600 

13,800 

15,800 

32,600 

50,100 

Cost of cleaning, 

24 certification 

$1,300 

2,000 

2,500 

3,400 

6,150 

Total 

cost 

$ 8,900 

15,800 

18,300 

36,000 

56,300 

Costs are in first-quarter 1979 dollars. 

Gulf Coast installation. 

cSelf-supporting aluminum dome costs include removal of platform and ladder 

as well as addition of new rim angle. 

3 

to 

Iii! 

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Table 7-19. COST OF INSTALLING A CONTACT INTERNAL FLOATING ROOF 

IN AN EXISTING NONCONTACT INTERNAL FLOATING-ROOF TANK3 

Tank 

Installed capital 

cost of an aluminum 

dimensions contact internalg 

(meters) floating roof ' 

Cost of 

Cost of clean- removing 

ing, degassing, noncontact 

d certifica- internal 2 B 

tion24 floating roof 

$1,300 

2,000 

2,500 

3,400 

6,150 

$ 600 

1,000 

1,100 

2,000 

2,700 

Total 

cost 

$11,200 

18,300 

21,200 

37,800 

57,800 

8 x 12 

13 x 15 -

14 x 17 

21 x 12 

27 x 15 

$ 9,300 

15,300 

17,500 

32,400 

48,950 

Costs are in first-quarter 1979 dollars. 

Diameter by height. 

cGulf Coast installation. 

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Table 7-20. COST OF INSTALLING A SECONDARY SEAL ON AN 

EXISTING INTERNAL OR EXTERNAL FLOATING ROOFa 

P.9 

Tank b 

dimensions 

(meters) 

8 x 12 

13 x 15 

14 x 17 

21 x 12 

27 x 15 

Installed capital 

cost of 24 

secondary seal 

$ 3,810 

5,520 

6,400 

8,690 

10,500 

Cost of cleaning, 

degassing, and. 

certification 

$1,300 

2,000 

2,500 

3,400 

6,150 

Total 

cost 

$ 5,100 

7,520 

8,900 

12,090 

16,650 

Costs are in first-quarter 1979 dollars. 

•"Diameter by height. 

7-40 
' 

Table 7-21. COST OF INSTALLING A CARBON ADSORPTION 

AT AN EXISTING MODEL FACILITY3 

Carbon adsorption 

system components 

Piping, pressure switches, and 

backup pressure switches 

Two water seals and two backup 

water seals 

Two blowers and two backup 

blowers 

Benzene saturator and related 

equipment 

Carbon adsorption unit and 

related equipment 

Cleaning and degassing 

of tanks 

Total 

Large 

benzene 

producer 

$67,840 

12,480 

14,560 

62,140 

109,060 

18,000 

$284,080 

aCosts are in first-quarter 1979 dollars. 

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Small 

benzene 

producer 

$43,630 

12,480 

14,560 

62,140 

109,060 

8,400 

$250,270 

SYSTEM 

Benzene 

consumer 

or bulk 

storage 

terminal 

$27,490 

12,480 

14,560 

62,140 

109,060 

4,800 

$230,530 

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Table 7-22. COST OF INSTALLING A THERMAL OXIDATION SYSTEM 

AT AN EXISTING MODEL FACILITY3 

p.11 ] 

Thermal oxidation 

system components 

Large 

benzene 

producer 

Small 

benzene 

producer 

Benzene 

consumer 

or bulk 

storage 

terminal 

Piping, pressure switches 

and backup pressure 

swi tches 

$67,840 $43,630 $27,490 

Two water seals and two 

backup water seals 

Two blowers and two backup 

blowers 

Benzene saturator and 

related equipment 

Thermal oxidation unit 

and related equipment 

Cleaning and degassing of 

tanks 

Total 

12,480 

14,560 

62,140 

67,020 

18,000 

$242,040 

12,480 

14,560 

62,140 

67,020 

8,400 

$208,230 

12,480 

14,560 

62,140 

67,020 

4,800 

$188,490 

Costs are in first-quarter 1979 dollars. 

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benzene saturator and redundant pressure switches, water seals, and 

blowers. 

The capital cost required for each existing model facility to comply 

with the requirements of each control option is shown in Table 7-23. 

7.2.1.2 Annualized costs. The capital cost for each control option 

was annualized using a useful lifetime of 10 years for internal and 

30 external floating roofs and seals. All other hardware including fixed 

roofs, carbon adsorption systems, and thermal oxidation systems was 

assumed to have a useful lifetime of 15 years. No salvage value was used 

in estimating the annualized cost for any option. 

Using a 10 percent interest rate in conjunction with these useful 

lifetimes, the capital recovery rates are 16.27 percent and 13.15 percent 

for 10 years and 15 years, respectively. With the addition of a 4 percent 

rate for taxes, insurance, and administrative expenses, the capital 

recovery rates become 20.27 percent and 17.15 percent, respectively. 

A yearly maintenance charge of 5 percent of the installed capital 

cost was added when converting a fixed-roof tank to an internal floatingroof tank. No charge was assessed when converting an external floating-roof 

tank to an internal floating-roof tank. A yearly maintenance charge of 1 

percent of the installed capital cost was included in the costs for the 

options requiring the use of a vapor control system. 

When retrofitting a fixed-roof tank with an internal floating roof, 

it was assumed that the tank owner or operator would conduct biannual 

visual inspections of the internal floating roof through roof hatches on 

the fixed roof. These inspections were estimated to cost $200 annually. 

It was also assumed that an additional and more thorough inspection 

inside each tank would be conducted at least once every 5 years at an 

estimated cost of $1,000, including the costs for cleaning and degassing 

the tank. This 5-year inspection was projected to have an annualized 

cost of approximately $200. Owners or operators of all tanks other than 

fixed-roof tanks were assumed to already have similar inspection schedules 

For the control options requiring the use of vapor control systems, 

utility expenses were estimated using electricity costs of $0.04/kWh, 

natural gas costs of $0.07/m3, and steam costs of $7.23/Mg. It was also 

31 

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